Tweet reply generator, and why replies stay in network
A tweet reply generator can write the text. It cannot put that reply on the For You page of people who do not follow you. A reply under someone else’s post does not enter that person’s followers’ For You through the open-source pipeline. The filter is explicit. The same tree also discounts replies that do stay in network. Both facts are in X_ALGORITHM_BOOST_PLAYBOOK.md, from xai-org/x-algorithm commit cb45b55.
tweet-factory will draft reply-shaped variants. tf generate asks for ideas aimed at copy-link, reply, quote, or follow. Text that starts with @ is scored as a reply: reply weight 5, not the mutual-original 20 (src/rank/score.ts). You still publish it yourself. The tweet generator page is the drafting tool. This page is the distribution limit.
Out of network, the reply is dropped
OONRetweetReplyFilter removes reposts and replies from accounts the viewer does not follow. EnablePhoenixOonReplies defaults false, so a reply to someone who does not follow you is not an out-of-network For You candidate.
Replies whose parent failed to hydrate are dropped for everyone, followers included.
A protected author is a separate rule: protected_author drops the post when the viewer does not follow them. A protected account gets no out-of-network For You distribution. Followers can still be shown the post.
Thunder, the in-network source, does keep a replies deque. Return cap in thunder/config.rs: 30 replies per author, beside 50 originals and 100 videos. That is “posts from accounts this viewer follows,” not “replies this author left on a stranger’s post, shown to the stranger’s audience.”
In network, a reply is scored lower than an original
When the viewer does follow the author, a reply or a repost is still multiplied by OonWeightFactor 0.75. EnableOonRescoreForInNetworkRepliesRetweets defaults true. An original post from a followed account is ×1.
The mutual-follow reply boost does not apply to a reply you send. CandidateScoringInputs::bidirectional_boost_eligible requires !is_reply && !is_retweet. The +15 on the reply head (5.0 + 15.0 = 20.0) is for an original post whose author the viewer mutually follows.
So the large “reply” coefficient is mostly “will this viewer reply to this original,” not “this reply should travel.”
One post per conversation
DedupConversationFilter keeps a single post per conversation id. The highest score wins. A reply can beat its own thread starter, and then the starter is the one that drops. Later posts in a thread compete with the first post and with each other.
That is why the playbook says the first post has to stand alone. It is a dedup rule, not a claim about thread length and virality.
What the code does not say
It does not say replies are worthless inside the group that already follows you. Reply’s coefficient on an in-network original is still 5.0, or 20.0 when the follow is mutual. It does not say a reply is invisible to the person you replied to, or to your followers via Thunder. It does not name RealGraph. That string is not in the repo.
src/tui/persona.ts writes algorithmPriorsBlurb() from src/rank/weights.ts into persona/PERSONA.md. That blurb says out-of-network replies are filtered, and that the reply weight is 20 on an original a mutual follow sees. It does not name RealGraph. The ranker facts on this page are the source of that blurb.
Related
FAQ
Can a tweet reply generator get replies onto non-followers’ feeds?
No path in this pipeline does that. OONRetweetReplyFilter drops replies and reposts from accounts the viewer does not follow, and EnablePhoenixOonReplies defaults false. A generated reply has the same filter as a reply you typed. The generator changes the wording. It does not change the filter.
Why don't replies reach non-followers?
OONRetweetReplyFilter drops replies and reposts from accounts the viewer does not follow, and EnablePhoenixOonReplies defaults false. A reply on a stranger’s post is not an out-of-network For You candidate in this pipeline. If the parent tweet fails to hydrate, the reply is dropped for followers too.
Does the out-of-network discount also hit replies to your own followers?
Yes. A reply or repost from an account the viewer follows is multiplied by 0.75, because EnableOonRescoreForInNetworkRepliesRetweets defaults true. An original from a followed account is not discounted. The +15 mutual reply boost applies to that original, not to a reply.
Can a reply outrank the start of a thread?
Yes. Conversation dedup keeps the highest-scoring post in the conversation. A reply can be the one that remains, and the thread starter is then ineligible for that request.